I have a 1ghz 14" ibook that is about 3.5 years old. Recently it has had issues where it freezes a lot and the backlight will abrubtly turn off. Restarting the computer fixes both issues, but it is really annoying and only has been happening for the past week. I'm out of the apple care deadline. For what it's worth, I did change the battery a few months ago with one made by a third party. The battery always gave me the problem of not warning me that the battery was about to die. I'm not sure if a faulty battery is causing this, but does anyone else have any suggestions to try? EDIT: It doesn't matter if it is plugged in or not because it happens with both. I also tried taking out the battery to see if the issues still occur, but it just really slowed down the computer to the point of being unusable.